JP-A-2004-218633 discloses a high-pressure fuel pump including a plunger being movable to draw fuel into a compression chamber. The plunger is configured to pressurize the fuel in the compression chamber to pump the fuel. The high-pressure fuel pump includes a valve element, which is located between a fluid passage and the compression chamber for controlling flow of the fuel drawn into the compression chamber. The valve member is operated by a solenoid actuator. The solenoid actuator is configured to bias the valve element via a needle to lift the valve element from a valve seat portion. When the solenoid actuator is energized, the needle is moved toward a coil portion of the solenoid actuator. When the needle is moved, the valve element is not exerted with force from the needle. In this condition, the valve element is seated to the valve seat portion by being exerted with pressure of fuel in a compression chamber. Consequently, the valve element isolates the fluid passage from the compression chamber.
The high-pressure fuel pump in JP-A-2004-218633 includes a stopper, which is located farther away than the valve element with respect to the valve seat portion so as to regulate movement of the valve element. The stopper has a communication hole for communicating a compression chamber with an interior around the valve element. In the present structure, the stopper is applied with dynamic pressure of fuel when the fuel is returned from the compression chamber to a fluid passage through the valve seat portion. Consequently, the valve element needs to be exerted with large force to maintain the valve element lifted from the valve seat portion when fuel is returned from the compression chamber to a fuel chamber. In the present structure, the valve element needs to be exerted with large biasing force from a biasing member of the solenoid actuator. Accordingly, the biasing member and the solenoid actuator are increased in size.
According to US 2004/0055580 A1 (WO0047888), a high-pressure fuel pump includes a valve element, which is located between a fluid passage and a compression chamber for controlling flow of the fuel drawn into the compression chamber. The valve element is a bottomed cylindrical member accommodating a spring as a biasing member. The spring is axially resilient to bias the valve element toward a valve seat portion.
In the structure of US 2004/0055580 A1, the valve element has a cavity for accommodating the spring. The cavity of the valve element communicates with the compression chamber through a passage. Therefore, when the plunger moves upward to pressurize fuel in the compression chamber fuel in the cavity of the valve element needs to be pressurized. That is, fuel in the cavity of the valve element needs to be additionally pressurized, and consequently, efficiency of pumping fuel is impaired.